While most drapery rod installations use straight drapery rods, there are some installations such as bowed and bay windows and room corners in which it is desirable to bend or curve the rod to conform to the windows or corners. Drapery rod installations in bow windows require bending the drapery rod to a relatively large radius of a curvature corresponding to that of the bow window, while bay windows and corners involve bending of the rod in one or more sections to a relatively small radius of curvature, for example of the order of 12 or 15 inches, with other sections of the drapery rod remaining generally straight. The radius of curvature of bow windows and the angles and size of the individual sections of bay windows vary in different installations, and it is generally necessary to custom bend the rod for each different installation.
Conventional metal drapery rods are difficult to bend without distorting the drapery trackway, especially in small radius bends of the order of 12 or 15 inches. It has been proposed to bend some drapery rods formed of metal by using bending tools similar to pipe bending tools and a flexible filler member which is inserted into the drapery rod before bending to reduce distortion of the trackway, and removed from the drapery rod after bending. It has also been proposed to bend steel drapery rods by forming a series of thin vertical cuts part way through the rod at the inner side of the bending curve so that the rod can be segmentally bent down to a relatively small radius curve. However, the slits weaken the drapery rod section and, to maintain strength, two rod sections are used, one inside the other.
It has also been proposed to form drapery rods of plastic, for example as disclosed in U.S. Pat. No. 3,346,227. In order to provide adequate strength for supporting the draperies, the rod must be formed of a plastic material that is rigid at normal room temperatures and with wall sections sufficiently thick to provide adequate strength for supporting the draperies. Drapery rods formed of rigid plastic material such as rigid polyvinylchloride, are flexible and can be bent at normal room temperatures, but tend to straighten when the bending forces are released. The rod mounting brackets cannot reliably hold such resilient plastic rod members in small radius curves such as 12 or 15 inches. In order to produce small radius curves with a more permanent bend in such plastic drapery rods, it has been proposed to submerge the section of the rod to be bent in hot water at a temperature and for a time sufficient to heat the plastic material to a softening temperature; remove the rod from the water; bend the rod to the desired curve, and thereafter hold the rod in the bent condition until it cools and sets. This not only requires a tank or receptacle of sufficient size to submerge at least the section of the rod to be bent, and means for heating and maintaining the water heated to a temperature sufficient to soften the plastic, but also presents the potential hazard of user burns from the hot water and/or heated plastic rod.